viernes, 22 de abril de 2011

NASA/Europe Space Agency Zero In On Planet's Melting Sea Ice

NASA/Europe Space Agency Zero In On Planet's Melting Sea Ice:


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ESA and  NASA have joined forces to further our understanding of how the fragile polar environment is responding to climate change in support of ESA's CryoSat ice mission, which was launched a year ago to monitor changes in ice thickness.

The one-month Arctic expedition is a major undertaking to ensure that CryoSat is delivering accurate data, with scientific teams from numerous organisations braving temperatures of –30°C in central Greenland, Svalbard and the Fram Strait, Devon Island and offshore from Alert, Ellesmere Island, in northern Canada.

Data on changes in the thickness of ice floating in the polar oceans and in the vast ice sheets on land are vital to deepen our understanding of the delicate relationship between ice, climate change and sea-level rise. 


As part of a collaborative effort, one of NASA's P-3 aircraft took part in the validation campaign by carrying out a joint flight with ESA planes as CryoSat passed overhead and ground teams took simultaneous measurements on ice floating in the Arctic Ocean. 

In total, there were four aircraft taking part along the same survey line over the Arctic sea ice.

ESA's validation campaign is now about 10 days into the first leg of the venture. The main effort, so far, has been in northern Canada and the Arctic Ocean. Weather permitting, ground teams have been out in force taking measurements of snow and ice on the ground to compare later with airborne data.

A Twin Otter aircraft from the Technical University of Denmark carries an instrument called ASIRAS,  developed specifically to mimic the radar altimeter on the CryoSat satellite. It emits a series of radar pulses as the plane travels over the ice and snow surfaces, recording the faint return echoes from the surface. It is an essential tool for understanding the interaction between the CryoSat radar echoes and ice and snow. 

In addition, a Basler-67 from the Alfred Wegner Institute tows an electromagnetic sensor called EM-Bird, which hangs below the plane close to the ground. This torpedo-shaped sensor measures ice thickness over the ground sites along CryoSat's track. 




Provided by The Daily Galaxy / ecnmag.com